Fluorescence of cereal flours

Front-surface fluorescence spectra of cereal flours are easily measured wit h a commercial spectrofluorometer and a simple cell. The emission spectra a re intense in the range 290-600 nm in which three emission bands are active . The most intense is due to the aromatic amino acid residues present in th e proteins of flours. At least two other fluorophores are active in the abo ve spectral range and compete for light with the chromophores present in th e flours. Four absorption bands are revealed in the same spectral region by reflectance spectra, the mast intense being due to the amino acidic fluoro phores. Thus, the measured emission is the result of absorption? scattering , emission, and reabsorption processes. Information on the microenvironment of some fluorophores can be obtained. The possibility to recognize differe nt species of cereals, even of different cultivars, is shown.